Terry Gray wrote:
<<
Any reason to think that Matthew isn't giving an eyewitness account
here? Sure, he may be using Mark as source material but if he was
there to witness the event for himself he could be adding details
that he saw for himself.
>>

Along similar lines, I was thinking that
Matthew's editing may have consisted of exageration
more than fabrication.

For example, we all know the cartoons where Willy
Coyotee goes flying over the edge of a cliff but
keeps going in a parallel direction for some time.
Then he looks around, and then down, and it is that
moment that he makes the vertical drop. All this
defies physics, but it gets its point across.

So could we take the "haggadic midrash" (or what ever), to mean that
Peter actually did jump out of the boat
(that is certainly consistent with the character of
Peter in the four gospels), and in actually, he _immediately_ sank
into the water, but Matthew, in
a mode of exaggeration, described it as "getting down and walking
toward Jesus (NIV)", looking around ("seeing the winds"), then
looking down ("was afraid"), and then plumps ("beginning to sink").

In that case, rather than "fabrication", I would see the "theological
editing" to be a case where Peter
didn't in fact walk on the water, but it describes
in very graphic terms something we all understand very
well. Admittedly, the purpose for the editing may have been for much
deeper reasons than simply to add that
memory factor, but that is all part of the best kind of writing.